Electric incandescent lamp



(No Model.)

J. H. GUEST.

ELBGTRIG INGANDESOENT LAMP.

Patented May 30, 1882.

UNITED STATES PATENT OFFICE.

JOHN H. eUEsT, or BROOKLYN, NEW YORK.

ELECTRIC INCANDESCENT LAMP.

SPECIFICATION forming part of Letters Patent No. 258,747, dated May 30,1882.

(No model.)

To all whom it may concern:

Be it known that I, JOHN H. GUEs'r, of Brooklyn, in the county of Kingsand State of New York, have invented an Improvement in ElectricIncandescent Lamps, of which the following is a specification.

I have heretofore employed one globe inside another, and also a fillingof lead between the glass nipple and the conducting-wires, as set forthin applications for patents heretofore made by me.

The object of the present invention is, first, to connect the innerglobe to the outer one in such a firm and reliable manner that there isno risk of the inner globe being displaced or the connection of the twoinjured under the ordinary circumstances of handling; second, to supportthe conductors within the lobe in such a firm manner that there will notbe any strain upon the carbon while being secured to the conductors orwhen being introduced into the globe, and risk of injury to the carbonby concussion in transportation or handling is avoided; third, to moreperfectly remove all traces of atmospheric air from the lam p-globes andto make a more perfect and reliable vacuum than heretofore in the globecontaining the carbon filament, and in cases where the outer globe isbroken the lamp may still be available, because the vacuum is maintainedin the inner globe.

In the drawings, Figure 1 is a section of a lamp containing myimprovements. Fig. 2 is a plan of the same without the cap. Fig. 3 is apartial section, in larger size, of the escapeopening from the innerglobe; and Fi 4 is a similar section with such opening hermeticallyclosed.

The conductors are composed of the wires a a, which will usually be ofcopper, except at the ends that project outside the outer globe, wherethey terminate preferably with platinum. These wires forming eachconductor are carefully twisted together, as shown, and covered withglass at b b,and there is a glass bridge, 0, that connects the glasscases I; of the wires and keeps them at the proper distance apart and intheir correct relative positions. The carbon filament is connected withthe ends of the respective metal conductors. This is usually done bycarbonaceous materials, and when a deposit of metal is made upon thebases of the carbon the glass cases for the conductors and the bridgefacilitate the handling of the conductors and the carbon during theplating operation.

The globe d is of any desired shape, preferablyof the elongated formshown. There are three or tour hollow glass nipples, 0 cl 0, made at thebase of the globe d. The conductors a a are passed through the nipples ce, and retained therein by lead or similar metal drawn into the nipplein a melted state and caused to adhere to the glass and to the metalwires, so as to form a perfectly-tightjoint, and one that will not beliable to crack when in use, because the metal in contact with the glasswillnot become heated at any time by the passing electric current.

The outer globe, l, is of a shape correspond ing generally with theinner globe, but larger, and it is provided with three or four hollowteats, n 12,1), and g, at its base, corresponding in position with theteats c c i 0, but rather larger. When the inner globe is placed in theouter globe the wires to a are passed through the teats n n and securedby the glass being melted around the said wires, so as to be perfectlyair-tight; or the wires may be secured in the outer globeteats by lead,as aforesaid. The teat i passes into the teat p, and the two are meltedtogether for the twofold purpose of hermetically sealing both globes atthe point and also of forming a firm connecting leg or support for theglobe at inside the globe l. The teat 0 passes into the teat q. The endof the latter is hermetically sealed, as shown in Fig. 3; but the end ofthe teat 0 is left open. The outer globe is properly shaped to inclosethe globe l, and there is a tube at m, (see dotted lines, Fig. 1,) bywhich the apparatus is connected with any suitable air-pump orexhausting apparatus.

In removing the airI exhaustthe glass globe,

the air passing outot the inner globe through I the teat 0 into theouter globe. When a good vacuum is obtained I admit hydrocarbon gasuntil atmosphericpressure, or nearly so, is ob tained. Then I exhaustthe said gas and ob tain a good vacuum. Hydrocarbon gas is againadmitted and partially exhausted, and the electric current is now passedthrough the carbon filament and the same gradually raised to the desiredincandeseenee, and a good vacuum obtained during the operation. Then thetube to the pump is hermetically sealed by melting the glass. As it isno longer necessary to maintain an opening in the inner globe, the teat0 is hermetically sealed, and at the same time connected with the teat gby melting the two together, as seen in Fig. 4, which at the same timeforms a strong connection for maintaining the inner globe in its properposition to the outer globe.

The outer globe may be ornamented by figures or designs engraved oretched upon its surface.

The cap or base piece If is preferably of glass, and it is of a sizesufficient to receive within it the teats.

The parts are to be united by plaster or any suitable substance pouredinto the cap around the nipples, after the introduction of a narrowpacking of cotton or similar material between the cap and the nipples.

The lamps may be placed so as to stand above the cap or base piece t; orthey may be placed, as shown, so as to hang down below the base or pointof support.

If desired, the lamps may be exhausted with the base uppermost. In thisinstance it is preferable to melt off the tube to the air-pum p. Thenturn the lamp with the base downward, apply the current to the carbon toheat any remaining air or gas, and cause it to pass down and out of theopen teatointo the outer globe, Z, and then the inner globe is sealed,as before described.

I am aware that two glasses have been applied around an electric lamp,such glasses being attached at their edges to the separate base-pieces.I do not claim an internal glass or globe and an external glass or globecombined with an ineandescing filament and leading in wires passing intosuch globes and sealed, whether such globes are exhausted or whetherthey are not. By my improvement I am able to make each glass globewholly of glass, without any base-piece, and of nearly uniform thicknessthroughout, and to connect the glass of the inner and of the outerglobes permanently together.

I claim as my invention 1. The metal conductors for an electric lampcased with glass inside the globe and united by the glass cross-bar,substantially as set forth.

2. The combination, in an electric lamp, of the globe, the metalconductors, the glass cases covering such conductors, the carbonfilament, and the lead or similar metal surrounding the conductors andwithin the glass teats ot' the globe, substantially as set forth.

3. In an electric lamp, the combination, with the inner and the outerglass globes, o't' teats through which the metallic conductors pass, andone or more projections or teats on the inner globe projecting intoglass teats on the outer globe, and the glass melted together forsupporting the inner globe in its proper position to the outer globe, asset forth.

4. The method herein specified of exhausting and hermetically sealingthe inner globe of an electric lamp, consisting in providing an openteat on the inner globe, passing into a closed teat on the outer globe,exhausting both globes, and then hermetically sealing the parts bymelting the glass of the outer and inner teats together, substantiallyas set forth.

5. In an electric lamp, two globes made wholly of glass, and each globebeing of nearly-uniform thickness throughout, and the glass of theglobes contracted around the conductors, and the two globes exhausted ofair and each hermetically sealed, in combination with the conductorspassing through the globes, and the incandescing filament within theinner globe, substantially as set forth.

Signed by me this 22d day of December, A. D. 1881.

J. H. GUEST.

Witnesses:

GEO. T. PINOKNEY, CnAs. H. Srrrrrr.

